A conventional gym includes a bench board mounted on a frame to be seated or slept by a user, and a weight lifting means formed on the frame lifted by a user's hand for physical training purpose, which however may have the following drawbacks:
1. A plurality of heavy weights are slidably held on two weight columns to be lifted by the trainee to easily cause vibration of the columns which are not reinforced with any side ribs secured to two rear supporting columns of the gym. If it is expected to secure the weight columns of the weights onto the rear supporting columns, several ribs or plates must be provided to horizontally link the weight columns to the rear columns. However, the weights, of which each weight is not formed with any side notch therein, must be slidably reciprocated on the weight columns and will be obstructed by the reinforcing ribs linked between the weight columns and the rear columns so that the weight quantity placed on the machine will be quite limited to thereby limit the weight-lifting capacity and training efficiency for the trainee.
2. The bench board is fixedly mounted on the frame and is not adjustable, thereby limiting the machine for a single training use such as merely for training a trainee's chest muscle or possible reducing a training interest of the trainee.
The present inventor has found the drawbacks of a conventional gym and invented the present adjustable weight lifting machine.